Cannot read from file

Question

I'm having a problem reading an integer from a file. As for my knowledge it should work. Can you tell me what have I done wrong here?

 int fileCount = 0; ifstream listFileStream ( fileName ); if ( listFileStream.is_open() ) { listFileStream >> fileCount; cout << fileCount; }

It only prints 0 even though the first line of the file is 28.

If I change the variable type to string it gives this... 'fileCount = "ÿþ2"' — Sanka Darshana
– Sanka Darshana, Commented Nov 28, 2013 at 6:19
@SankaD I think you have some unexpected characters at the start of your file. Could even be the Byte Order Mark (BOM). — john
– john, Commented Nov 28, 2013 at 6:20
Ah... I deleted the file and copied the content into a new file with the same name and now it works... Thanks. — Sanka Darshana
– Sanka Darshana, Commented Nov 28, 2013 at 6:23

Dietmar Kühl · Accepted Answer · 2013-11-28 06:56:07Z

You should always check that you read attempt was successful:

if (listFileStream >> fileCount) { process(fileCount); }

If the read isn't successful you can try to recover from it or report an error. Here is one way you might try to recover: restore the stream to good state and ignore the first character:

listFileStream.clear(); listFileStream.ignore();

Without restoring the stream to a good state all input attempts would be ignored. Once the offending character is removed you would retry the read.

Collectives™ on Stack Overflow

Cannot read from file

1 Answer 1

Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Related